Styracosaurus
Styracosaurus ("spiked lizard"Liddell & Scott (1980). Greek-English Lexicon, Abridged Edition. Oxford University Press, Oxford, UK. ISBN 0-19-910207-4.) was a ceratopsian dinosaur from the Late Cretaceous Period.﻿ It was distinguished by having a large, horned neck frill and one large horn on its nose. Description Styracosaurus was about 5.5 meters long and weighed approximately 2.7 tons.Lambert, D. (1993). The Ultimate Dinosaur Book. Dorling Kindersley: New York, 152–167. ISBN 1-56458-304-X. Its most distinctive feature was its head, which was large and had a neck frill adorned with a number of horns, from which the dinosaur gets its name. These spikes can be more than 50 centimeters long.Dodson, P. (1996). The Horned Dinosaurs: A Natural History. Princeton: Princeton University Press. pp. 165–169. ISBN 0-691-05900-4. The nose horn was usually even longer. As with most ceratopsians, Styracosaurus had a smaller horn on each cheek. The limb positions of Styracosaurus and other ceratopsians is uncertain, and both upright and sprawling positions have been proposed. Current research suggests it was somewhere in between these two extremes.Thompson, Stefan; and Holmes, Robert (April 2007). "Forelimb stance and step cycle in Chasmosaurus irvinensis (Dinosauria:Neoceratopsia". Palaeontologia Electronica. Retrieved 2007-05-28. Classification Styracosaurus was part of the ceratopsian subfamily Centrosaurinae, which is distinguished by prominent nose horns and subordinate brow horns, among others.Tweet, J. (2007). "Centrosaurinae". Thescelosaurus. Qwest.net. Retrieved 2007-04-22. Because centrosaurine classification is often based solely upon head ornamentation, determining species is difficult, and even differences among skulls could possibly be attributed to sexual dimorphism.Sampson, S. D.; Ryan, M.J.; and Tanke, D.H. (1997). "Craniofacial ontogeny in centrosaurine dinosaurs (Ornithischia: Ceratopsidae): taphonomic and behavioral phylogenetic implications". Zoological Journal of the Linnean Society 121 (3): 293–337. doi:10.1111/j.1096-3642.1997.tb00340.x. In fact, one species of Styracosaurus, S. ovatus, was placed into a new genus, Rubeosaurus, in 2010.Andrew T. McDonald & John R. Horner, (2010). "New Material of "Styracosaurus" ovatus from the Two Medicine Formation of Montana", In: Michael J. Ryan, Brenda J. Chinnery-Allgeier, and David A. Eberth (eds), New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium, Indiana University Press, 656 pp. Currently, only the type species of Styracosaurus, S. albertensis, is valid.Lambe, L.M. (1913). "A new genus and species from the Belly River Formation of Alberta". Ottawa Naturalist 27: 109–116. Below is a 2011 cladogram that shows the position of Styracosaurus within the Centrosaurinae:McDonald, A. T. (2011). "A Subadult Specimen of Rubeosaurus ovatus (Dinosauria: Ceratopsidae), with Observations on Other Ceratopsids from the Two Medicine Formation". In Farke, Andrew Allen. PLoS ONE 6 (8): e22710. doi:10.1371/journal.pone.0022710. PMC 3154267. PMID 21853043. |2= |4= }} }} }} }} }} }} }} }} }} Discovery '' Styracosaurus'' was first discovered by the fossil hunter Charles M. Sternberg in what is now Dinosaur Provincial Park in Alberta, Canada. S. albertensis was named by Lawrence Lambe in 1913. Two years later, the paleontologist Barnum Brown discovered a second skeleton in the same formation. He compared it to the holotype and found it different enough to erect a new species for his find, S. parksi, after the paleontologist William Parks.Brown, Barnum; Erich Maren Schlaikjer (1937). "The skeleton of Styracosaurus with the description of a new species". American Museum novitates (New York City : The American Museum of Natural History) no. 955: 12. Retrieved 2007-03-29. However, it is now considered to be another specimen of S. albertensis.Ryan, Michael J.; Holmes, Robert; and Russell, A.P. (2007). "A revision of the late Campanian centrosaurine ceratopsid genus Styracosaurus from the Western Interior of North America". Journal of Vertebrate Paleontology 27 (4): 944–962. doi:10.1671/0272-4634(2007)27944:AROTLC2.0.CO;2. Retrieved 2010-08-19. The skeleton is still on display in the American Museum of Natural History. Charles Gilmore described another species of Styracosaurus, S. ovatus, in 1930 from the Two Medicine Formation of Montana. The fossil material was incomplete, but it seemed to have shorter horns than S. albertensis.Gilmore, Charles W. (1930). "On dinosaurian reptiles from the Two Medicine Formation of Montana". Proceedings of the United States National Museum 77 (16): 1–39. In 2010, Andrew McDonald and Jack Horner reassigned the species to its own genus, Rubeosaurus. Paleobiology Styracosaurus is often considered to be a herd animal, which is supported by fossil evidence. A bonebed of the dinosaur exists in the Dinosaur Park Formation, which lies in a river deposit.Eberth, David A.; and Getty, Michael A. (2005). "Ceratopsian bonebeds: occurrence, origins, and significance". In Currie, Phillip J., and Koppelhus, Eva. Dinosaur Provincial Park: A Spectacular Ancient Ecosystem Revealed. Bloomington: Indiana University Press. pp. 501–536. ISBN 0-253-34595-2. There are many hypotheses as to how and why the animals gathered here.Rogers, R. R. (1990). "Taphonomy of three dinosaur bone beds in the Upper Cretaceous Two Medicine Formation, northwestern Montana: Evidence for drought-related mortality". PALAIOS 5 (5): 394–41. doi:10.2307/3514834. JSTOR 3514834. Greg Paul and Per Christiansen have suggested that large ceratopsians like Styracosaurus could run faster than an elephant at times, based on evidence from trackways.Paul, Gregory S; Per Christiansen (September 2000). "Forelimb posture in neoceratopsian dinosaurs: implications for gait and locomotion". Paleobiology (BioOne) 26 (3): 450–465. doi:10.1666/0094-8373(2000)026<0450:FPINDI>2.0.CO;2. Retrieved 2007-02-25. Diet Like its relatives, Styracosaurus was probably herbivorous, although it has been suggested that some ceratopsians were at least partially omnivorous.Naish, D. (1999). EVIL FANGED CERAPODANS Archives of the Dinosaur Mailing List, November 19, 1999. Its jaws bore a deep, narrow beak that was probably better suited to grabbing or plucking than biting.Ostrom, J. H. (1966). "Functional morphology and evolution of the ceratopsian dinosaurs". Evolution 20 (3): 290–308. doi:10.2307/2406631. JSTOR 2406631. Unlike those of hadrosaurids, ceratopsid teeth sliced but did not grind.Dodson, P., Forster, C. A, and Sampson, S. D. (2004) Ceratopsidae. In: Weishampel, D. B., Dodson, P., and Osmólska, H. (eds.), The Dinosauria (second edition). Berkeley: University of California Press, pp. 494–513. ISBN 0-520-24209-2. Ornamentation The horns and frill of Styracosaurus makes it one of the most distinctive of dinosaurs, and several hypotheses for their purpose have been proposed. In 1908 R. S. Lull proposed that the giant frills of ceratopsians were used to anchor large jaw musclesLull, R.S. (1908). "The cranial musculature and the origin of the frill in the ceratopsian dinosaurs". American Journal of Science 4 (25): 387–399. doi:10.2475/ajs.s4-25.149.387., a theory that, although once supported, has now been mostly abandoned.Forster, C. A. (1990). The cranial morphology and systematics of Triceratops, with a preliminary analysis of ceratopsian phylogeny. Ph.D. Dissertation. University of Pennsylvania, Philadelphia. 227 pp. One of the most popular theories was that the horns of Styracosaurus and other ceratopsians were used to defend themselves from predators, while the frill protected the vulnerable area of the neck. The horns could also be used in combat with other members of the species. Scratches and pitting found on ceratopsian skulls seemed to support these ideas. However, in 2006, a study attributed these scratches to bone resorption or disease.Tanke, D. H, and Farke, A. A. (2006). Bone resorption, bone lesions, and extracranial fenestrae in ceratopsid dinosaurs: a preliminary assessment. in: Carpenter, K. (ed.). Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs Indiana University Press: Bloomington. pp. 319–347. ISBN 0-253-34817-X. Even, there is still valid evidence supporting intra-species combat in at least some types of ceratopsian.Farke A.A., Wolff E.D.S., Tanke D.H., Sereno Paul (2009). Sereno, Paul. ed. "Evidence of Combat in Triceratops". PLoS ONE 4 (1): e4252. doi:10.1371/journal.pone.0004252. At the current time, the most widely accepted theory for the purpose of ceratopsian ornamentation is for sexual display. This explains the fact that the horns and frill of different species of ceratopsian varied widely in size, shape, and placement. Modern animals that exhibit such adornment also use them for display purposes, strengthening this theory.Farlow, J. O., and Dodson, P. (1975). "The behavioral significance of frill and horn morphology in ceratopsian dinosaurs". Evolution 29 (2): 353–361. doi:10.2307/2407222. JSTOR 2407222. In popular culture Because of its distinctive horns and frill, Styracosaurus is one of the most recognizable dinosaurs, and is one of the more famous ceratopsians after Triceratops. It has appeared in various films such as The Valley of Gwangi, where a Styracosaurus fights the Allosaurus title character; The Land That Time Forgot, and the Disney film Dinosaur. Styracosaurus is also mentioned in the first Jurassic Park novel, although it is never seen. The animal makes several appearances in games and television series. References Category:Animals Category:Dinosaurs Category:Ceratopsians Category:Herbivores Category:Fossil taxa described in 1913